Process for hydrophobicizing particles, and their use as fillers in polymer masterbatches

ABSTRACT

Particles are hydrophobicized by treatment with a compound containing amino and silane groups, followed by treatment with a silane compound containing a hydrophobic group. The invention is particularly useful for treating hydrophilic mineral particles. The treated particles can be used, for example, as fillers in polymer masterbatches.

BACKGROUND OF THE INVENTION

1. Field of the Invention

In one of its aspects, the present invention relates to thehydrophobicizing of particles, particularly mineral particles that arehydrophilic and have surface hydroxyl groups, for example silica,silicates, clay, alumina, titanium dioxide and the like. The inventionalso extends, however, to treatment of non-mineral particles, forinstance carbon black. In another of its aspects, the present inventionalso relates to the treated partices, per se. The treated particles areuseful particularly, but not exclusively, as a filler in polymers,especially rubber. In another of its aspects, the present invention,also relates to a filled, particularly silica-filled, rubbermasterbatch, and to a process for preparing it.

2. Description of the Prior Art

In recent years, there has developed a considerable interest in silicareinforced tires, particularly since the appearance in 1992 of theGroupe Michelin (G-M) patents (EP 05 01 227 A 1; AU-A-111 77 192)indicating that tires made with tread formulations incorporating silicaenjoy some important performance advantages over those based onconventional carbon black filler. Improvements are claimed for this“Green Tire” in the areas of (a) lower rolling resistance, (b) bettertraction on snow, and (c) lower noise generation, when compared withconventional tires filled with carbon black.

Rubber for tires is often supplied by a rubber producer to a tiremanufacturer in the form of a masterbatch containing an elastomer, whichis typically a hydrocarbon rubber, an oil extender and a filler. Theconventional filler has been carbon black in the form of fine particles.These particles have hydrophobic surface characteristics and willtherefore disperse relatively easily within the hydrophobic elastomer.In contrast, conventional silica has a relatively hydrophilic surface,and considerable difficulty has been encountered in dispersingconventional silica in the hydrophobic rubber elastomer.

In the past, efforts have been made to make masterbatches from elastomerdispersions and aqueous dispersions of silica pigment, such as thosereferred to and attempted by Burke, in U.S. Pat. No. 3,700,690. Burkeattempted to overcome the previously known difficulties of incorporatingfine particles of silica uniformly into a masterbatch. At the time ofthe Burke invention, there was no known elastomer-silica masterbatchoffered in the commercial market. Similarly today, to the Applicant'sknowledge, there are no commercially available in situ producedelastomer-silica masterbatches in the market, despite the efforts ofBurke (i.e., conventional elastomer-silica masterbatches are producedand available in the dry state).

SUMMARY OF THE INVENTION

It is an object of the present invention to obviate or mitigate at leastone of the above-mentioned disadvantages of the prior art.

It is another object of the present invention to provide a novel,relatively hydrophobic particulate material.

It is yet another object of the present invention to provide a novelprocess for treating particulate material to render it relativelyhydrophobic.

It is yet another object of the present invention to provide a novelmasterbatch composition comprising an elastomer and a relativelyhydrophobic particulate material.

It is yet another object of the present invention to provide a novelprocess for producing a masterbatch composition comprising an elastomerand a relatively hydrophobic particulate material.

Accordingly, in one of its aspects, the present invention provides aprocess for treating particles, particularly mineral particles, torender them hydrophobic, the process comprising the steps of:

(a) contacting the particles with a compound of Formula I:

 or an acid addition or quaternary ammonium salt thereof, in which:

at least one of R¹, R² and R³, preferably two of R¹, R² and R³ and mostpreferably R¹, R² and R³ are hydroxyl or hydrolysable groups;

R⁴ is a divalent group that is resistant to hydrolysis at the Si—R⁴bond;

R⁵ is selected from the group comprising: hydrogen; C₁₋₄₀ alkyl; a C₂₋₄₀mono-, di- or tri-unsaturated alkenyl group; a C₆-C₄₀ aryl group; agroup of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴, which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³ which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula:

—[(CH₂)_(r)NH]_(d)—H

 wherein r is an integer from 1 to 6 and d is an integer from 1 to 4;

R⁶ may be any of the groups defined for R⁵, or R⁵ and R⁶ may togetherform a divalent group of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀ alkenyl group, a C₆-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and v are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6, and is preferably 4; and

(b) contacting the particles with a compound of the Formula II:

 in which:

R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³; and

R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or a C₈₋₄₀mono-, di- or tri-unsaturated alkenyl group, either of which can beinterrupted by one or more aryl groups, preferably phenyl groups; agroup of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, for example the phenylene group —(C₆H₄)—, thebiphenylene group —(C₆H₄)—(C₆H₄)—, the —(C₆H₄)—O—(C₆H₄)— group or thenaphthylene group, —(C₁₀H₆)—, the aromatic group being unsubstitued orsubstituted by a C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturatedalkenyl group; and R²⁰ may be any of the groups defined for R¹⁹, withthe provisos that R¹⁹ and R²⁰ do not have a tertiary carbon atomadjacent to the nitrogen atom and that at least one of R¹⁹ and R²⁰ has acarbon chain at least 8 carbon atoms in length uninterrupted by anyheteroatoms.

Preferably, R¹⁸ is a C₁-C₄₀ saturated or unsaturated group (e.g.,alkenyl, aryl, cycloalkyl and the like).

In the present process, Steps (a) and (b) may be conducted concurrentlyor sequentially. If Steps (a) and (b) are conducted sequentially, it ispreferred to conduct Step (a) followed by Step (b).

As will be apparent to those of skill in the art, there are instanceswhere Formulae I and II may be the same compound—e.g., when R⁵=R¹⁹=aC₈₋₄₀ alkyl group or R⁵=R¹⁹=a C₈₋₄₀ mono-, di- or tri-unsaturatedalkenyl group. Thus, in such cases where Formulae I and II are the samecompound, it will be clearly understood that the present processintentionally embodies a single step process (i.e., where the compoundof Formulae I and II is added in a single step) and a multi-step process(i.e., where the compound of Formulae I and II is added proportionallyin two or more steps).

In another of its aspects, the present invention provides a treatedparticulate material comprising particles having bound thereto anaminohydrocarbonsiloxane (e.g., an amino(alkyl)siloxane) moiety—i.e., ahydrocarbon moiety comprising both silicon and nitrogen.

Preferably, the aminohydrocarbonsilane moiety has the formula

in which:

R^(a), R^(b) and R^(c) are the same or different and each is selectedfrom —O— and —C_(p)H_(2p)—, optionally substituted by one or more oxygenatoms and wherein p is an integer of from 1 to 10; and

R¹² is a C₈₋₄₀ alkyl group; a C₈₋₄₀ mono-, di- or tri-unsaturatedalkenyl group; a group of formula

 or an acid addition or quaternary ammonium salt thereof in which R⁴ isa divalent group resistant to hydrolysis at the Si—R⁴ bond, R⁵ ishydrogen, C₁₋₄₀ alkyl, C₂₋₄₀ mono-, di- or tri-unsaturated alkenyl; agroup of formula

—ArC_(w)H_(2w+1)

 in which Ar represents a divalent aromatic group and w is an integerfrom 1 to 20, and R⁶ may be any of the groups defined for R⁵, with theproviso that at least one of R⁵ and R⁶ must have an uninterrupted carbonchain at least 8 carbon atoms in length.

In yet another of its aspects, the present invention provides aparticulate material comprising particles having: (i) bound thereto anaminohydrocarbonsiloxane (e.g., an amino(alkyl)siloxane) moiety (i.e., ahydrocarbon moiety comprising both silicon and nitrogen), and (ii) acontact angle of at least about 100°. Preferably, theaminohydrocarbonsilane moiety has the formula set out hereinabove.Preferably, the particles have a contact angle of at least about 110°,more preferably in the range of from about 115° to about 160°, even morepreferably in the range of from about 120° to about 150°, mostpreferably in the range of from about 120° to about 140°. In contrast,the contact angle of silica particles which are not treated inaccordance with the present process is typically 75°.

The contact angle of the particles with water may be readily determinedaccording to the following procedure:

(i) double-sided tape is attached to a probe (e.g., a stirrup) andcoated with the particulate material by immersing the tape in a sampleof the particulate material;

(ii) excess powder is removed by gentle tapping and large powderclusters are removed by careful wiping;

(iii) the probe coated with particulate material is immersed intodistilled water using a conventional contact angle analyzer (e.g., aCahn Dynamic Contact Angle Analyzer) at a rate of 100 microns persecond.

This procedure results in determination of the advancing contact angleof the particles.

In yet another of its aspects, the present invention provides aparticulate material produced by contacting the particles with acompound of Formula I:

or an acid addition or quaternary ammonium salt thereof, in which:

at least one of R¹, R² and R³, preferably two of R¹, R² and R³ and mostpreferably R¹, R² and R³ are hydroxyl or hydrolysable groups;

R⁴ is a divalent group that is resistant to hydrolysis at the Si—R⁴bond;

R⁵ is selected from the group comprising: hydrogen; a C₁₋₄₀ alkyl; aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group; a C₆-C₄₀ aryl group;a group of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴, which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³ which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula:

—[(CH₂)_(r)NH]_(d)—H

 wherein r is an integer from 1 to 6 and d is an integer from 1 to 4;

R⁶ may be any of the groups defined for R⁵, or R⁵ and R⁶ may togetherform a divalent group of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀ alkenyl group, a C₆-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and v are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6, and is preferably 4;

and a compound of the Formula II:

in which:

R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³; and

R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or a C₈₋₄₀mono-, di- or tri-unsaturated alkenyl group, either of which can beinterrupted by one or more aryl groups, preferably phenyl groups; agroup of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, for example the phenylene group —(C₆H₄)—, thebiphenylene group —(C₆H₄)—(C₆H₄)—, the —(C₆H₄)—O—(C₆H₄)— group or thenaphthylene group, —(C₁₀H₆)—, the aromatic group being unsubstitued orsubstituted by a C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturatedalkenyl group; and R²⁰ may be any of the groups defined for R¹⁹, withthe provisos that R¹⁹ and R²⁰ do not have a tertiary carbon atomadjacent to the nitrogen atom and that at least one of R¹⁹ and R²⁰ has acarbon chain at least 8 carbon atoms in length uninterrupted by anyheteroatoms.

Preferably, the present process of treating a particulate material iscarried out in an aqueous solution, dispersion or slurry, so that theproduct of the process is an aqueous dispersion or slurry ofhydrophobicized mineral particles.

In one preferred embodiment, the dispersion or slurry resulting from thepresent process, and containing the treated particles (preferablymineral particles such as silica), is then mixed with a hydrocarbonsolution of an elastomer, and then dried to form a silica-filled rubbermasterbatch. Owing to the hydrophobicized nature of the silica filler,it is well dispersed in the elastomer. This preferred embodiment resultsin the in situ production of a masterbatch composition comprising theelastomer and the treated particles. By “in situ production” is meantthat treated particles are incorporated into a masterbatch compositionwithout being isolated (i.e., separated from the dispersion or slurry,and subsequently dried). This preferred embodiment is believed to be thefirst in situ production of a masterbatch composition comprising anelastomer and a treated particulate material such as silica.

Alternatively, the treated particulate material may be separated fromthe dispersion or slurry, and subsequently dried for later use.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described with reference toe accompanying drawings, in which:

FIGS. 1-4 illustrate a reaction pathway for a specific embodiment of theresent process;

FIG. 5 illustrates a schematic of a system used to conduct the presentprocess in the Examples hereinbelow.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Throughout this specification, the invention is illustrated withreference to silica as the particle having surface hydroxyl groups, butit should be appreciated that the invention applies to the use of othersuch minerals, and the description understood accordingly. For example,the present process may be applied to a particulate mineral materialselected from the group comprising silicates, silicas (particularlysilica made by carbon dioxide precipitation of sodium silicate), clay,titanium dioxide, alumina, calcium carbonate, zinc oxide and mixturesthereof. The present process may also be applied to a particulatenon-mineral material such as carbon black. Of course, mixtures ofparticulate materials may be used.

In a preferred embodiment, the treatment is carried out in an aqueousdispersion or slurry and the concentration of the aqueous dispersion orslurry of silica particles may be between 1 and 30 percent by weight ofsilica in water, preferably between 5 and 25 percent by weight of silicain water and most preferably between 8 and 22 percent by weight ofsilica in water. Dried amorphous silica suitable for use in accordancewith the invention may have a mean agglomerate particle size between 1and 100 microns, preferably between 10 and 50 microns and mostpreferably between 10 and 25 microns. . It is preferred that less than10 percent by volume of the agglomerate particles are below 5 microns orover 50 microns in size. A suitable amorphous dried silica moreover hasa BET surface area, measured in accordance with DIN (Deutsche IndustrieNorm) 66131, of between 50 and 450 square meters per gram and a DBPabsorption, as measured in accordance with DIN 53601, of between 150 and400 grams per 100 grams of silica, and a drying loss, as measuredaccording to DIN ISO 787/II, of from 0 to 10 percent by weight. Iffilter cake is used, it may be made by any known means such as describedin Ullmann's Encyclopedia of Industrial Chemical Vol A23 pages 642-643,VCH Publishers, ©1993. The filter cake has a preferred solids content ofbetween 5 and 30 percent by weight, most preferably between 15 and 25percent by weight, and it may be redispersed in water in accordance withthe present process to give a silica concentration of between 5 and 20percent by weight and most preferably between 8 and 12 percent byweight. It is preferred to use a filter cake.

If a never-filtered slurry prepared from the known reaction of asolution of alkali metal silicate with either mineral acid or carbondioxide is used, it is preferred that the solids content of thenever-filtered slurry be between 1 and 30, more preferably between 5 and10, percent by weight of silica. The slurry temperature may be between 0and 100 degrees Celsius if the process is conducted at atmosphericpressure or between 0 and 135 degrees Celsius if the operation isconducted in a pressure vessel. Most preferably, the process isconducted at atmospheric pressure in which case the preferredtemperature is between 30 and 95 degrees Celsius and most preferablybetween 45 and 90 degrees Celsius.

It is desirable that, prior to the addition to the silica particles ofthe compound of Formula I, the dispersion or slurry shall have a pH inthe range from 6 to about 8, more preferably from about 6.8 to about7.2. If necessary, the pH can be adjusted by addition of acid or alkali,for example mineral acid, alkali metal hydroxide, alkaline earthhydroxide, ammonium hydroxide and the like. These can be added as suchor in aqueous solution.

In the compound of Formula I, it is preferred that all three of thegroups R¹, R² and R³ are readily hydrolysable. Suitable groups R¹include hydroxyl groups and hydrolysable groups of formulaOC_(p)H_(2p)+1, where p has a value from 1 to 10. The alkyl chain can beinterrupted by oxygen atoms, to give groups, for example, of formulaCH₃OCH₂O—, CH₃OCH₂OCH₂O—, CH₃(OCH₂)₄O—, CH₃OCH₂CH₂O—, C₂H₅OCH₂O—,C₂H₅OCH₂OCH₂O—, or C₂H₅OCH₂CH₂O—. Other suitable hydrolysable groupsinclude phenoxy, acetoxy, chloro, bromo, iodo, ONa, OLi, OK or amino ormono- or dialkylamino, wherein the alkyl group(s) have 1 to 30 carbonatoms.

R² and R³ can take the same values as R¹, provided that only one of R¹,R² and R³ is chloro, bromo or iodo. Preferably, only one or two of R¹,R² and R³ is hydroxyl or ONa, OLi or OK.

Non-limiting examples of groups R² and R³ that are not hydrolysableinclude C₁₋₁₀ alkyl, C₂₋₁₀ mono- or diunsaturated alkenyl, and phenyl.R² and R³ can also each be a group —R⁴—NR⁵R⁶, discussed further below.It is preferred that R¹, R² and R³ are all the same and are CH₃O—,C₂H₅O— or C₃H₈O—. Most preferably they are all CH₃O—.

The divalent group R⁴ is preferably such that N—R⁴—Si is of the formula:

N—(CH₂)_(p)(O)_(o)(C₆H₄)n(CH₂)_(m)(CH═CH)_(k)—Si

in which k, m, n, o and p are all whole numbers. The order of themoieties between N and Si is not particularly restricted other thanneither N or O should be directly bound to Si. The value of k is 0 or 1,the value of m is from 0 to 20 inclusive, the value of n is 0, 1 or 2,the value of o is 0 or 1 and the value of p is from 0 to 20 inclusive,with the provisos that the sum of the values of k, m, n, o and p is atleast 1 and not more than 20 and that if o is 1, p is 1 or greater andthe sum of k, m and n is 1 or greater, i.e. that the Si atom is linkeddirectly to a carbon atom. There should be no hydrolysable bond betweenthe silicon and nitrogen atoms. Preferably, m is 3 and I, n, o and p areall 0, i.e., R⁴ is —CH₂CH₂CH₂—.

The group R⁵ is preferably a C₈₋₂₀ monounsaturated alkenyl group, mostpreferably a C₁₆₋₁₈ monounsaturated alkenyl group. R⁶ is preferablyhydrogen.

Suitable compounds of Formula I include, but are not limited to:3-aminopropylmethyldiethoxysilane,N-2-(vinylbenzylamino)-ethyl-3-aminopropyltrimethoxysilane,N-(2-aminoethyl)-3-aminopropyltrimethoxy-silane,trimethoxysilylpropyldiethylenetriamine,N-2-(aminoethyl)-3-aminopropyltris(2-ethylhexoxy)silane,3-aminopropyldiisopropylethoxysilane,N-(6-aminohexyl)aminopropyltrimethoxysilane,4-aminobutyltriethoxysilane, 4-aminobutyldimethylmethoxysilane,triethoxysilylpropyldiethylenetriamine,3-aminopropyltris(methoxyethoxyethoxy)silane,N-(2-aminoethyl)-3-aminopropyltrimethoxysilane,N-2-(aminoethyl)-3-aminopropyltris(2-ethylhexoxy)silane,3-aminopropyldiisopropylethoxysilane,N-(6-aminohexyl)aminopropyltrimethoxysilane,4-aminobutyltriethoxysilane, and(cyclohexylaminomethyl)-methyldiethoxysilane.

Preferred compounds of Formula I include those in which R⁵ is hydrogenand R⁶ is the alkenyl group from the following: soya alkyl, tall oilalkyl, stearyl, tallow alkyl, dihydrogenated tallow alkyl, cocoalkyl,rosin alkyl, and palmityl, it being understood that in this case thealkyl may include unsaturation.

It is preferred that at least one of R⁴, R¹³ and R¹⁴ has a chain of atleast 8 carbon atoms, more preferably at least 10 carbon atoms,uninterrupted by any heteroatom.

The compound of Formula I can be used as the free base, or in the formof its acid addition or quaternary ammonium salt, i.e.

wherein R¹, R², R³, R⁴, R⁵ and R⁶ are as defined above; R⁷ is selectedfrom the group comprising hydrogen, a C₁₋₄₀ alkyl group or C₂₋₄₀ mono-,di- or tri-unsaturated alkenyl group, and X is an anion. X is suitablychlorine, bromine, or sulphate, of which chlorine and bromine arepreferred, and R⁷ is preferably hydrogen.

Non-limiting examples of suitable salts of compounds of Formula Iinclude N-oleyl-N-[(3-triethoxysilyl)propyl]ammonium chloride,N-3-aminopropylmethyldiethoxysilane hydrobromide,(aminoethylamino-methyl)phenyltrimethoxysilane hydrochloride,N-[(3-trimethoxysilyl)propyl]-N-methyl, N-N-diallylammonium chloride,N-tetradecyl-N,N-dimethyl-N-[(3-trimethoxysilyl)propyl]ammonium bromide,3[2-N-benzylaminoethylaminopropyl]trimethoxysilane hydrochloride,N-octadecyl-N,N-dimethyl-N-[(3-trimethoxysilyl)propyl]ammonium bromide,N-[(trimethoxysilyl)propyl]-N-tri(n-butyl) ammonium chloride,N-octadecyl-N-[3-triethoxysilyl)propyl]ammonium chloride andN-2-(vinylbenzylamino)ethyl-3-aminopropyl-trimethoxysilanehydrochloride.

It is preferred to use the compound of Formula I in salt form. The mostpreferred compound is N-oleyl-N-[(3-trimethoxysilyl)propyl]ammoniumchloride.

The amount of the compound of Formula I may be between 0.1 and 20percent by weight of the mineral particles in the slurry (dry basis) andpreferably between 0.25 and 10 percent by weight and most preferablybetween 0.5 and 2 percent by weight. Preferably, the amount of thecompound of Formula I used varies inversely with the mineral particlesize. The compound may be added to the slurry in its natural state,either as a liquid or a solid. However, to facilitate dispersion, it ispreferred where possible to add the compound as a liquid. If the meltingpoint of the compound is below 95 degrees Celsius, it is preferred toadd it to the slurry in a molten state at a temperature at least 5degrees Celsius above the melting point, provided the temperature of thecompound in the liquified state does not exceed 100 degrees Celsius andprovided that the compound does not decompose under these conditions. Ifthe melting point exceeds 95 degrees Celsius, it is most preferred touse a solvent. Preferred solvents are water and alcohols containing 1 to5 carbon atoms and most preferably those containing 1 to 3 carbon atoms,that is to say methanol, ethanol, n-propanol or isopropanol. If thecompound of Formula I is an alkoxysilane, then most preferably thealkoxy group of the solvent alcohol will be the same as the alkoxy groupof the alkoxysilane. For example, if the compound of Formula I is amethoxysilane, the preferred solvent is methanol. The concentration ofthe compound in the solvent may be from 10 to 90 percent by weight andmore preferably between 25 and 75 percent by weight and most preferably50 percent by weight. Preferably, the solution can be prepared and addedto the slurry at a temperature between a lower limit of 0 degreesCelsius and an upper limit which is the lower of at least 10 degreesbelow the boiling point of the solvent and 95 degrees Celsius. Thedispersion of the compound is effected by mixing.

It is preferred that, for the specific compound of Formula I which isadded, the equivalent balance (EB) should be calculated. The EB is usedto determine whether mineral acid or alkali metal hydroxide, or solutionthereof, should be added. The equivalent balance (EB) may be determinedfrom the absolute value of the sum of the group values of X (ifpresent), R¹, R² and R³ and the magnitude of the sum of the groupcontributions of X (if present), R¹, R² and R³ together with the weightadded and the molecular weight of the compound of Formula I, accordingto the following scheme:

The group contribution of X for either X=Cl or X=Br is −1, thus, if X ispresent, it is given a value of −1. The group contribution of each ofR¹, R² and R³ is generally zero for all groups except as follows: if thegroup is CH₃COO, Cl or Br, in which case it is −1, or if it is amine(including an imine), ONa, OK or OLi in which case it is +1. If the sumof the group contributions for X, R¹, R² and R³ is zero, no adjustmentwith mineral acid or alkali metal hydroxide (or solutions thereof) isnecessary. If the sum of the group values is a positive integer,adjustment with mineral acid is desirable, and if it is negative,adjustment with alkali metal hydroxide is desirable.

For example, where R¹=OCH₃, R²=CH₃, R³=Cl and X=Br, the sum of the groupvalues (g.v.) is:

Σ=(g.v. OCH₃)+(g.v. CH₃)+(g.v. Cl)+(g.v. Br)=(0)+(0)+(−1)+(−1)=−2

The negative sign in front of the sum indicates adjustment with alkalimetal hydroxide is required. The number of equivalents of alkalirequired is given by the equivalent balance (EB) which includes theabsolute value of the sum of the group contributions (|Σ|) as a scalingfactor:${EB} = \frac{{\Sigma } \times {weight}\quad {in}\quad {grams}\quad {of}\quad {the}\quad {chemical}\quad {added}}{{molecular}\quad {weight}\quad {of}\quad {the}\quad {added}\quad {chemical}}$

In continuing the example, if a process according to the presentinvention were scaled so as to require 6,000 grams of a chemical ofFormula I with a molecular weight of 350 grams and the sum of the groupvalues gave −2, EB would be calculated as follows:

EB=−2×6000/350=−34.28 gram-equivalents

Thus, in this example, 34.28 gram-equivalents of alkali metal hydroxidewould be added. Sodium hydroxide is the preferred alkali metalhydroxide. The weight of sodium hydroxide would be:

Weight=(EB)×(Equivalent Weight of NaOH)=34.28×40.0=1371.2 grams

The preferred technique according to the invention is to dissolve thealkali metal hydroxide or mineral acid in water so as to obtain aconcentration between 5 and 25% by weight and most preferably between 5and 10% by weight prior to adding the solution to the slurry.

It is known to incorporate a coupling agent into rubber that is intendedto be vulcanized and used, for instance, in tires. Suitable couplingagents include those described in U.S. Pat. No. 4,704,414, publishedEuropean patent application 0,670,347A1 and published German patentapplication 4435311A1, the disclosures of each of which are incorporatedby reference. One suitable coupling agent is a mixture ofbis[3-(triethoxysilyl)propyl]monosulfane,bis[3-(triethoxysilyl)propyl]disulfane,bis[3-(triethoxysilyl)propyl]trisulfane andbis[3-(triethoxysilyl)propyl]tetrasulfane and higher sulfanehomologues—for example, coupling agents available under the trade namesSi-69 (average sulfane 3.5), Silquest™ A-1589 or Si-75 (average sulfane2.0). Another non-limiting examples of a suitable coupling agent isbis[2-(triethoxysilyl)ethyl]-tetrasulfane, available under the tradename Silquest RC-2. In the past, achieving a good balance between thecoupling agent and particles, such as silica, without scorching orpremature curing has proven difficult. In accordance with the invention,if particles, particularly silica particles, are being treated to renderthem hydrophobic for use in rubber which is subsequently to bevulcanized, it is possible to include a step of adding a coupling agentin the process of the invention, so that the coupling agent becomesattached to the surface of the hydrophobicized mineral particles andbecomes dispersed in the rubber with the mineral particles.

Thus, in some preferred embodiments of the invention, a coupling agentis added to the dispersion, more preferably after the addition of thecompound of Formula I but before the compound of Formula II is added. Asdiscussed above, in some cases, Formulae I and II may represent the samecompound. In these cases, it is preferred to add the coupling agentbetween sequential additions of the compound of Formulae I and II.

The coupling agent may be added after any addition of mineral acid oralkali metal hydroxide that is indicated by the calculation of the EB.Non-limiting examples of suitable coupling agents include compounds offormula:

R⁸R⁹R¹⁰MR¹¹

in which at least one of R⁸, R⁹ and R¹⁰, preferably two of R⁸, R⁹ andR¹⁰ and most preferably R⁸, R⁹ and R¹⁰, are hydroxyl or hydrolysablegroups. The groups R⁸, R⁹ and R¹⁰ are bound to the atom M, which issilicon, titanium or zirconium. The group R⁸ may be hydroxyl orOC_(p)H_(2p)+1 where p is from 1 to 10 and the carbon chain may beinterrupted by oxygen atoms, to give groups, for example, of formulaCH₃OCH₂O—, CH₃OCH₂OCH₂O—, CH₃(OCH₂)₄O—, CH₃OCH₂CH₂O—, C₂H₅OCH₂O—,C₂H₅OCH₂OCH₂O— or C₂H₅OCH₂CH₂O—. Alternatively R⁸ may be phenoxy. If Mis titanium or zirconium, R⁸ may be the neopentyl(diallyl)oxy group, butnot if M is silicon. The group R⁹ may be the same as R⁸. If M issilicon, R⁹ may also be a C₁₋₁₀ alkyl group, a phenyl group, or a C₂₋₁₀mono- or diunsaturated alkenyl group. If M is titanium or zirconium, R⁹may be the neopentyl(diallyl)oxy group, but not if M is silicon.Further, R⁹ may be the same as the group R¹¹ described below.

R¹⁰ may be the same as R⁸, but it is preferred that R⁸, R⁹ and R¹⁰ arenot all hydroxyl. If M is silicon, R¹⁰ may also be C₁₋₁₀ alkyl, phenyl,C₂₋₁₀ mono- or diunsaturated alkenyl. If M is titanium or zirconium, R¹⁰may be the neopentyl(diallyl)oxy group, but not if M is silicon. FurtherR¹⁰ may be the same as the group R¹¹ described below.

The group R¹¹ attached to M is such that it may participate in acrosslinking reaction with unsaturated polymers by contributing to theformation of crosslinks or by otherwise participating in crosslinking.In the case where M is silicon, R¹¹ may have one of the followingstructures: R¹¹ may represent the allyl group —H₂CCH═CH₂, the vinylgroup —CH═CH₂, the 5-bicycloheptenyl group or the group described by

—(alk)_(e)(Ar)_(f)S_(i)(alk)_(g)(Ar)_(h)SiR⁸R⁹R¹⁰

where R⁸, R⁹ and R¹⁰ are the same as previously defined, alk is adivalent straight hydrocarbon group having between 1 and 6 carbon atomsor a branched hydrocarbon group having between 2 and 6 carbon atoms, Aris either a phenylene —C₆H₄—, biphenylene —C₆H₄—C₆H₄— or —C₆H₄—OC₆H₄—group and e, f, g and h are either 0, 1 or 2 and i is an integer from 2to 8 inclusive with the provisos that the sum of e and f is always 1 orgreater than 1 and that the sum of g and h is also always 1 or greaterthan 1. Alternately, R¹¹ may be represented by the structures(alk)_(e)(Ar)_(f)SH or (alk)_(e)(Ar)_(f)SCN where e and f are as definedpreviously. Moreover, it is possible for R¹¹ to have the structure

—(CH═CH)_(k)(CH₂)_(m)(C₆H₄)_(n)(O)_(o)(CH₂)_(p)R¹³

wherein k, m, n and o and p are all whole numbers and R¹³ represents theacryloxy CH₂═CHCOO— or the methacryloxy CH₂=CCH₃COO— group. Further, thevalue of k may be 0 or 1, m may be from 0 to 20 inclusive, n may bebetween 0 and 2, o may be 0 or 1, and p may be from 0 to 20 inclusive,with the provisos that the sum of k, m, n and o is at least 1 and notgreater than 20, and that if n is 1 or 2 or o is 1, p is 1 or greater.It is most preferable that m=3 and k, n, o and p are all 0.

Preferably, R⁸, R⁹ and R¹⁰ are all either OCH₃, OC₂H₅ or OCH₈ groups andmost preferably all are OCH₃ groups. It is most preferred that thecoupling agent is bis[3-(trimethoxysilyl)propyl]tetrasulfane (Si-168).The amount of coupling agent to add is optional; levels between 2 and 10percent by weight of the silica in the slurry (dry basis) are preferred.The dispersion of the chemical may be effected by mixing.

Non-limiting illustrative examples of other coupling agents include thefollowing: bis[(trimethoxysilyl)propyl)]disulfane (Si-166),bis[(triethoxysilyl)propyl)]-disulfane (Si-266),bis[2-(trimethoxysilyl)ethyl]-tetrasulfane,bis[2-(triethoxysilyl)ethyl]trisulfane,bis[3-(trimethoxysilyl)propyl]disulfane,3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldi-ethoxysilane,3-mercaptoethylpropylethoxymethoxysilane,1,3-bis(3-acryloxypropyl)tetramethoxydisiloxane,acryloxypropylmethyldimethoxysilane,3-methacryloxypropyl-trimethoxysilane, allyltrimethoxysilane,diallyldiethoxysilane, 5-(bicycloheptenyl)triethoxysilane,5-(bicycloheptenyl)methylmethoxyethoxysilane,isopropoxytriacryltitanate, diisopropyldimethacryltitanate,diethoxydi(3-mercaptopropoxy)zirconate,triisopropoxy-(2-mercaptoethoxy)zirconate, anddi[neopentyl(diallyl)oxy]-di(3-mercaptopropoxy)-zirconate.

Other preferred coupling agents include those disclosed in publishedGerman patent application 44 35 311 A1, On pages 2 and 3, there isdisclosure of oligomers and polymers of sulphur containingorganooxysilanes of the general formula:

in which R¹ is a saturated or unsaturated, branched or unbranched,substituted or unsubstituted hydrocarbon group that is at leasttrivalent and has from 2 to 20 carbon atoms, provided that there are atleast two carbon-sulphur bonds, R² and R³, independently of each other,are saturated or unsaturated, branched or unbranched, substituted orunsubstituted hydrocarbon groups with 1 to 20 carbon atoms, halogen,hydroxy or hydrogen, n is 1 to 3, m is 1 to 1000, p is 1 to 5, q is 1 to3 and x is 1 to 8.

Preferred compounds are of the general formula

wherein R², m and x have the meanings given above, and R² is preferablymethyl or ethyl. These compounds disclosed in German Patent ApplicationNo. 44 35 311 A1 are preferred coupling agents for use in the presentinvention.

Also preferred for use in this invention are coupling agents disclosedin the abovementioned published European patent application 0,670,347A1,which discloses coupling agents of the general formula:

R¹R²R³S^(i)—X¹—(—S_(x)—Y—)_(m)—(—S_(x)—X²—SiR¹R²R³)_(n)

in which R¹, R² and R³ are the same or different and are C₁₋₈ alkyl,C₁₋₈ alkoxy, phenyl or phenoxy, provided that at least one of R¹, R² andR³ is an alkoxy or phenoxy group. X¹ and X² are the same or differentand are divalent linear or branched, optionally unsaturated C₁₋₁₂ alkylgroups, Y is a di-, tri- or tetravalent linear, branched or cyclic C₁₋₁₈alkyl group that is optionally unsaturated and is optionally substitutedby C₆₋₁₂ aryl, C₁₋₈ alkoxy or hydroxy groups and which can beinterrupted by oxygen, sulphur or nitrogen atoms or aromatic C₆₋₁₂ arylgroups, or Y is a C₆₋₁₂ aryl or heteroaryl group, m is an integer from 1to 20, n is an integer from 1 to 6 and x is an integer from 1 to 6.

Particularly preferred coupling agents are those of the followinggeneral formulae:

(RO)₃SiCH₂CH₂CH₂S_(x)—CH₂CH₂_(n)S_(x)—CH₂CH₂CH₂Si(OR)₃

in which R=—CH₃ or —C₂H₅, x=1-6 and n=1-10;

in which R=—CH₃ or —C₂H₅, x=1-6 and n=1-10;

 (RO)₃SiCH₂CH₂CH₂S_(x)—(CH₂)₆_(n)S_(x)—CH₂CH₂CH₂Si(OR)₃

in which R=—CH₃, —C₂H₅ or —C₃H₇, n=1-10 and x=1-6;

in which R=—CH₃, —C₂H₅ or —C₃H₇, n=1-10 and x=1-6;

in which R=—CH₃, —C₂H₅ or —C₃H₇, n=1-10 and x=1-6;

(RO)₃Si—CH₂CH₂CH₂S_(x)—CH₂CH₂OCH₂CH₂_(n)S_(x)—CH₂CH₂CH₂Si(OR)₃

in which R=—CH₃, —C₂H₅, —C₃H₇, n=1-10 and x=1-6;

in which R=—CH₃, —C₂H₅, or —C₃H₇, n=1-10 and x=1-6;

in which R=—CH₃, —C₂H₅, or —C₃H₇; R¹=—CH₃, —C₂H₅, —C₃H₇, —C₆H₅, —OCH₃,—OC₂H₅, —OC₃H₇ or —OC₆H₅, n=1-10 and x=1-8; and

(RO)₃Si—CH₂CH₂CH₂S_(x)—(CH₂)₆_(r)S_(x)—(CH₂)₈_(p)CH₂CH₂CH₂Si(OR₃)

in which R=—CH₃, —C₂H₅ or —C₃H₇, r+p=2-10 and x=1-6;

Especially preferred are coupling agents of the formulae:

(RO)₃SiCH₂CH₂CH₂S_(x)—(CH₂CH₂)₆_(n)S_(x)—CH₂CH₂CH₂—Si(OR)₃

in which x is 1-6 and n is 1-4.

In Step (b) of the present process, the compound of Formula II is addedto the particulate filler material. Again, it is preferred that theparticulate filler material, more preferably a mineral filler, is in theform of an aqueous slurry or a dispersion, and the compound of FormulaII is added to the slurry or dispersion under intense mixing. In thecompound of Formula II the possible and preferred values for R¹⁵, R¹⁶and R¹⁷ are the same as the possible and preferred values for R¹, R² andR³ that are discussed above in relation to Formula I. If R¹² is an aminogroup of formula —R¹⁸—NR¹⁹R²⁰, preferred values for R¹⁸ are such thatN—R¹⁸—Si includes groups of the formula:

N—(CH₂)_(p)(O)_(o)(C₆H₄)_(n)(CH₂)_(m)(CH═CH)_(k)—Si

in which k is 0 or 1, m is 0 to 20 inclusive, n is 0, 1 or 2, o is 0 or1 and p is 0 to 20 inclusive, provided that the sum of k, m, n, o and pis at least 1 and not greater than 20, and further provided that if o is1, p is also 1 or greater, and the sum of k, m and n is 1 or greater.The order of the moieties between N and Si is not particularlyrestricted other than neither N or 0 should be directly bound to Si.There should be no hydrolysable group between the silicon and nitrogenatoms. Preferably k, n, o and p are all 0 and m is 3, i.e. R¹⁸ is—CH₂CH₂CH₂—.

R¹² may be a moiety containing at least one primary, secondary, ortertiary amine nitrogen. In this case the amino group bonded to R¹⁸— isgiven by the formula —NR¹⁹R²⁰. R¹⁹ may be a H or a C₁₋₄₀ alkyl group ora C₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group. R¹⁹ may also be aC₁₋₂₀ alkyl-substituted or C₂₋₂₀ alkenyl-substituted aromatic group. Thearomatic group may be, for example, the phenylene group —(C₆H₄)13 , thebiphenylene group —(C₆H₄)—(C₆H₄)—, the —(C₆H₄)—O—(C₆H₄)— group, or thenaphthylene group —(C₁₀H₆)—. R²⁰ may be one of the same groups as R¹⁹with the further proviso that at least one of R¹⁹ and R²⁰ must contain acontinuous carbon chain of at least 8 carbons in length, uninterruptedby any heteroatoms.

As stated above, if R¹⁹ and R²⁰ are other than hydrogen, the carbon atomattached to the nitrogen atom is not tertiary. Preferably the carbonatom attached to the nitrogen atom is primary, i.e., —CH₂—.

It is preferred that R¹⁹ is a mono-unsaturated alkenyl group of 12-20carbons in length and most preferable that R₁₉ is a monounsaturatedalkenyl group of 16 to 18 carbons in length. It is most preferable alsothat R²⁰ is H.

Alternatively, R¹² may be a moiety which contains a mineral acid salt ora quaternary ammonium salt of an amine. The formula of R¹² may thus bedescribed by the extended formula —R¹⁸—NR¹⁹R²⁰-R²¹x wherein —R¹⁸—, R¹⁹and R²⁰ are as previously defined and R²¹ may be a H, or a C₁₋₄₀ alkylor C₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group and X is an anion,preferably Cl or Br, although sulphate can be used.

There is the further proviso that at least one of R¹⁹ and R²⁰ mustcontain a continuous carbon chain of at least 8 carbons in length,uninterrupted by any heteroatom. It is preferred to use an amine saltwhere R¹⁹ is a mono- or di-unsaturated alkenyl group of 12-20 carbons inlength and most preferably that R¹⁹ is a mono- or di-unsaturated alkenylgroup of 16 to 18 carbons in length. It is most preferable also that R²⁰is H and that R²¹ is H and X is chlorine. The preferred hydrophobicizingagent of Formula II is N-oleyl-N-(3-trimethoxysilyl)propyl ammoniumchloride.

Preferably, the amount of the hydrophobic compound of Formula II to addis generally between 0.5 and 20 percent by weight of the weight of theparticles (preferably mineral particles such as silica) in the slurry(dry basis), and is inversely proportional to the particle size of thesilica particles. The compound may be added to the slurry in its naturalstate, either as a liquid or a solid. However, to facilitate dispersion,it is preferred, where possible, to add the compound as a liquid. If themelting point of the compound is below 95 degrees Celsius, it ispreferred to add it to the slurry in a molten state at a temperature atleast 5 degrees Celsius above the melting point, provided thetemperature of the compound in the liquified state does not exceed 100degrees Celsius and provided that the compound does not decompose underthese conditions. If the melting point exceeds 95 degrees Celsius, it ismost preferred to use a solvent. Suitable solvents are alcoholscontaining 1 to 5 carbon atoms and most preferably those containing 1 to3 carbon atoms, that is to say methanol, ethanol, n-propanol orisopropanol. If the compound of Formula II is an alkoxysilane, mostpreferably the alkoxy group of the solvent alcohol will be the same asthe alkoxy group of the alkoxysilane. For example, if the compound ofFormula II is a methoxysilane, the preferred solvent is methanol. Theconcentration of the compound in the solvent may be from 10 to 90percent by weight and most preferably between 25 and 75 percent byweight and most preferably 50 percent by weight. Preferably, thesolution is prepared and added to the slurry at a temperature between alower limit of 0 degrees Celsius and an upper limit which is the lowerof at least 10 degrees below the boiling point of the solvent and 95degrees Celsius.

After the addition of the hydrophobic compound of Formula II which isadded, the equivalent balance (EB) should be calculated to determine howmuch, if any, mineral acid or alkali metal hydroxide (or solutionsthereof) to add. The equivalent balance (EB) may be determined from theabsolute value of the sum of the group values of X, R¹⁵, R¹⁶ and R¹⁷ andthe weight added, and the molecular weight of the compound, according tothe following scheme: The group contribution of X for either X=Cl orX=Br is −1, thus if X is present it is given a value of −1. The groupcontribution of each of R¹⁵, R¹⁶ and R¹⁷ is generally zero for allgroups except as follows: if the group is CH₃COO^(⊖), CI^(⊖) or Br^(⊖),in which case it is −1, or if it is amino, ONa, OK, or OLi in which caseit is +1. If the sum of the group contributions for X, R¹⁵, R¹⁶ and R¹⁷is zero, no adjustment with mineral acid or alkali metal hydroxide (orsolutions thereof) is necessary. If the sum of the group values is apositive integer, adjustment with mineral acid is desirable, and if itis negative, adjustment with alkali hydroxide is desirable.

For example, where R¹⁵=OC₂H₅, R¹⁶=OCH₃ R¹⁷=CH₃ and X=Cl, the sum Σ ofthe group values (g.v.) is:

Σ=(g.v. OC₂H₅)+(g.v. OCH₃)+(g.v. CH₃)+(g.v. Cl)=(0)+(0)+(0)+(−1)=−1.

The negative sign in front of the sum indicates adjustment with alkalimetal hydroxide is required. The number of equivalents of alkalirequired is given by the equivalent balance (EB) which includes theabsolute value of the sum of the group contributions (|Σ|) as a scalingfactor.${EB} = \frac{{\Sigma } \times {weight}\quad {in}\quad {grams}\quad {of}\quad {the}\quad {compound}\quad {added}}{{molecular}\quad {weight}\quad {of}\quad {the}\quad {added}\quad {{chemical}.}}$

In continuing the example, if a process according to the presentinvention were scaled so as to require 3450 grams of a compound ofFormula II with a molecular weight of 466 grams and the sum of the groupvalues gave −1, EB would be calculated as follows:

EB=|−1|×3450/466=7.4 gram-equivalents.

Thus, in this example, 7.4 gram-equivalents of alkali metal hydroxidewould be added. Sodium hydroxide is the preferred alkali metalhydroxide. The weight of sodium hydroxide added would be:

Weight=(EB)×(Equivalent Weight of NaOH)=7.4×40.0=296 grams.

The preferred technique according to the invention is to dissolve thealkali hydroxide or mineral acid in water so as to obtain aconcentration between 5 and 25% by weight and most preferably between 5and 10% by weight prior to adding the solution to the slurry. Thetemperature of the solution may be from 0 degrees Celsius to 100 degreesCelsius under atmospheric pressure, or if a pressure vessel is used forpreparation of the solution, it may be from 0 degrees Celsius to 130degrees Celsius. It is preferred that the temperature of the solution bewithin 10 degrees of the solution of the slurry. The dispersion of thesolution in the slurry is effected by mixing.

While not wishing to be bound by any particular theory or mode ofaction, it is believed that the mechanism of the present process oftreating particulate materials can be illustrated as shown in FIGS. 1-4.In this illustrative reaction scheme, silica is shown as the particulatematerial being treated with a specific compound falling within FormulaeI and II defined hereinabove. Of course, FIGS. 1-4 are provided forillustrative purposes only and should not be used to limited the scopeof the invention.

With reference to FIG. 1, there is illustrated an initial step in thepresent process. As illustrated, an adduct of 3-CPTMS/oleylamine¹,preferably in the form of a methanolic solution, is added to an aqueousslurry of silica particles. The methoxy silane linkages in the adductare readily hydrolysed by water or by contact with the acidic surfacesilanol groups on the silica resulting in condensation of the adduct onthe surface of the silica particles.

¹N-(3-trimethoxysilylpropyl)-N-(octadec-9-enyl) ammonium chloride, theproduction of which is discussed in a copending Internationalapplication filed on even date herewith in the name of the Applicant,the contents of which are hereby incorporated by reference.

With reference to FIG. 2, a preferred step in the present process isillustrated. Specifically, an active surface-bound catalyst is preparedby neutralization of the hydrochloride salt with a base (NaOH is shown).The strongly basic amine so produced is believed to further react withsurface silanols resulting in deprotonation of the latter, as shown.

With reference to FIG. 3, another preferred step in the present processis illustrated. Specifically, a coupling agent commercially availableunder the tradename Si-69² is added to the active surface-bound catalystproduced in FIG. 2. Preferably, the coupling agent is added slowly (thisminimizes self-condensation) and under high shear conditions (thisfacilitates dispersion). The deprotonated silanol groups readily reactwith the ethoxy moieties on the Si-69 releasing ethanol and regeneratingthe active catalyst (not shown). The process continues until the Si-69coupling agent has reacted. The condensed Si-69 moieties may linkseveral silica particles together (see FIG. 4 and discussion below) or,in the case of larger particles or agglomerates, substantially allcondensed endgroups may be attached to the same particle.

²While bis[3-(triethoxysilyl)propyl]tetrasulfane is shown in FIG. 3, asdiscussed hereinabove, those of skill in the art recognize that Si-69 ismixture of bis[3-(triethoxysilyl)propyl]monosulfane,bis[3-(triethoxysilyl)propyl]disulfane,bis[3-(triethoxysilyl)propyl]trisulfane andbis[3-(triethoxysilyl)propyl]tetrasulfane (average sulfane 3.5).

With reference to FIG. 4, after sufficient time has been allowed for theSi-69 coupling agent to react to completion, additional3-CPTMS/oleylamine adduct is added to react with most of the remainingresidual silanol groups (FIG. 1). Preferably, this is again followed byneutralization with a base (FIG. 2). The long alkyl groups now attachedto the surface of the silica particle render the particle stronglyhydrophobic and thus more compatible with, inter alia, a hydrocarbonpolymer cement. Further, the bulky alkyl groups attached to the silicaparticles serve to sterically limit the interaction of water moleculeswith the surface.

The process described thus far provides an aqueous slurry or dispersionof hydrophobicized silica (i.e., it has not yet been contacted with anelastomer or other substrate to be filled), which can be used as such orcan be filtered and dried. Hydrophobicized silica can be used as afiller in a multitude of materials including, but not limited to, thefollowing: elastomers, alkyd paints, as a component of antifoamingpreparations or foam regulators in laundry detergents, or as toners suchas those used in photocopiers, and rubber vulcanizates. Mention is madeparticularly of tire treads and of shoe soles.

In a preferred embodiment of this invention the hydrophobicized silica,in the aqueous dispersion or slurry, is incorporated into a polymer, forexample an elastomer to form a rubber masterbatch. It is particularlypreferred that the hydrophobicized silica shall have been treated with acoupling agent, for example Si-69, Si-168 or Silquest RC-2, as discussedabove. The slurry is mixed with a hydrocarbon or other solution of theelastomer. Preferably, the solvent in which the elastomer is dissolvedis immiscible with, or mostly immiscible with, water to form a preblend.This elastomer solution may be made by dissolving the solid elastomer ina solvent, or it may be the solution resulting from the polymerisationof monomers in the solvent. The elastomer may be a hydrocarbon rubber, agraft polymer or block polymer of monomers having at least oneethylenically unsaturated bond and polymerizable through thisunsaturation. Other suitable polymers include, but are not limited toIIR, HIIR, IR, EPDM, SBR, BR, NBR, HNBR, HSRE, natural rubber,polystyrene, polychloroprene, epichlorohydrin (ECO), chlorinatedpolyethylene, silicone and ABS. Suitable solvents include but are notlimited to cyclohexane, hexane, benzene, toluene and pentane.Optionally, processing oil and antioxidants may be added to thehydrocarbon solution prior to mixing with the slurry, or they may beadded after mixing the slurry and the elastomer solution.

The viscosity of the final elastomer solution, sometimes referred to asan elastomer cement, containing the optional ingredients is preferablysuch that it closely matches the viscosity of the silica slurry and isgenerally between 1,000 and 50,000 centipoise. The temperature of theelastomer solution is preferably the same as that of the slurry and theamount of cement that is added is such that the final masterbatch maycontain from 5 to 250 parts of silica per hundred parts of elastomer,preferably from 35 to 100 parts of silica per hundred parts ofelastomer, most preferably from 60 to 80 parts of silica per hundredparts of elastomer.

The elastomer cement and, optionally, oil and antioxidants, is mixedwith the silica slurry until the mixture becomes homogeneous and themilky colour of the silica slurry disappears to form a preblend. A smallamount of water may separate at this stage.

If not added previously, or if additional amounts are desired, oil andantioxidants may be added next and the mixing continued further untilthe oil and antioxidant become incorporated in the continuous phase.

Any water which separates from the preblend may be removed, discarded orrecycled for silica slurry make-up by stopping the agitator for asuitable period and allowing the water phase to accumulate in the bottomof the mixing tank from which it may be drained prior to proceeding withthe next step. Agitation is preferably restarted after the water layeris removed.

If antioxidants and processing oil were not previously added, or ifadditional amounts are desired, they may be added at this stage andstirring continued until the preblend is again homogeneous.

The preblend is then added to water heated to a temperature equal to, orpreferably higher than the boiling point of the solvent used for theelastomer cement so as to remove the solvent and produce a masterbatchcoagulum in the form of a crumb suspended in water. The preferabletemperature of the water prior to addition of the preblend is between 50and 100 degrees Celsius, most preferably between 90 and 95 degreesCelsius, and the preblend is added at a rate so as to maintain aso-fixed or reasonably so-fixed water temperature throughout thecoagulation. The agitation is set sufficiently high so as to maintainthe crumb in a suspended state within the water but not so high as tocause the crumb to subdivide into particles smaller than approximately 5millimeters.

The solvent may be recovered from the coagulator by recondensing thevapours. The material containing the suspended crumb is passed through afilter screen sized so as to recover the wet masterbatch. The materialpassing through the screen may be optionally recycled for further silicaslurry make-up.

The wet crumb is dried such as by using forced air or fluidized bed ormicrowave drying techniques at a temperature between about 75 and about135 degrees Celsius, preferably between about 85 and about 120 degreesCelsius, most preferably between about 85 and about 105 degrees Celsius,until a suitably dry masterbatch crumb is obtained.

The dried crumb may be further processed according to industry andcustomer requirements.

Preferred embodiments of the invention are illustrated by the exampleswhich follow. The examples can be interpreted with the aid of FIG. 5which illustrates an arrangement for carrying out a masterbatch processembodiment of the invention, according to Examples I and II The legendin FIG. 5 is as follows:

R1: A balance-mounted portable paint pot of nominal capacity 120 liters.The pot is equipped with a Strahman (piston) bottom valve (Vs), anoversized air-operated motor, one 6-inch radial flow agitator (top) andone 10-inch marine impeller (bottom) on a single shaft, and an externalsteam coil (J) for heating. The lower impeller has approximately 2inches of clearance from the bottom of R1; the top impeller is attachedat a point 9 inches higher. A valved chemical addition port (P1) isavailable on the removable lid and the pot may be purged with nitrogenthrough another port (N1) when transfer of the contents is required. Awater line may be coupled to an additional port (W). A portable exhaustsnorkel (E) is available in the vicinity to remove fugitive methanol andethanol emissions. R1 is used for the silica slurry makeup and as avessel to carry out the described additions to produce a hydrophobicizedsilica slurry.

T1: A nominal 500 USG glass-lined chemical reactor used for cementmake-up and storage and as a mixing vessel for the silica slurry andpolymer cement prior to coagulation. It is equipped with a 200 rpmpneumatic drive, a marine impeller and heating jacket to speeddissolution of rubbers. It has various addition ports including: M, asmall manhole for introducing rubber and oil, P2, for solvent (hexane)addition, a nitrogen line port (N2) for pressure transfer of thecontents through a large bottom drain with a valve (V2). The bottomvalve is located a short distance from the tank bottom in order toreduce dead space in the piping.

H: Armoured flex hose, 2 inch diameter, for slurry and cement transfers.

V1: A 3-way valve to control the direction of flow.

T2: A steam coagulator of nominal capacity 400 liters. It is equippedwith a steam sparge port near the bottom and a connection to servicewater. An overflow port (P3) and overflow channel are situated close tothe top to allow for product discharge. A large pipe at the top directssolvent vapours to a condenser (C). The tank is stirred by means of anair operated motor and an 8-inch diameter marine impeller. S: A 24-inchdiameter Sweco® shaker screen (100 mesh).

C: A condenser for solvent recovery from coagulation. It is connected tocold process water through a valve (V4).

T3: A solvent decanter, approx. 250 USG, for recycle solvent storage andwater separation. A valve (V3) allows for sampling and water discharge.

T4: A 60 liter plastic tank for fines settling.

G: Perforated trays for product dewatering and drying.

Ex: A short (24″ long, 3-inch diameter screw) dewatering extruder“Rocket” powered by an explosion proof motor via a variable speedgearbox.

Embodiments of the present invention will be described with reference tothe following Examples which should not be used to limit the scope ofthe invention.

EXAMPLE I

1) Cement Preparation

A hydrocarbon solution of polybutadiene (˜16 wt %) was prepared byadding 66.9 kg of a high cis-polybutadiene rubber (Taktene 1203),previously cut into small pieces, to 351 kg cyclohexane in T-1. Themixture was stabilized by adding 0.5 kilos each of a hydroperoxidescavenger (Polygard) and a hindered phenol antioxidant (Irganox 1076)and dissolution was effected by heating to 60 degrees Celsius withstirring for 2 days. It was then allowed to cool to ambient temperaturein the absence of agitation.

2) Hydrophobicized Silica Slurry Preparation

The recipes/procedures used are shown in Table I, which follows.

The agitation rate on R1 was set at ˜250 rpm during all steps on each ofthe four days.

TABLE 1 Preparation of Hydrophobicized Silica Slurry Sub-StepParameters: DAY 1 DAY 2 DAY 3 DAY 4 a) Slurry preparation Water (kg)53.5 53.5 53.5 53.5 Water Temperature 65 64 61 58 (° C.) HiSil-233silica (kg) 13.4 13.4 13.4 13.4 Stirring time (mins) 5 5 5 5 FinalTemperature (° C.) 58 57.8 56.2 52 b) Addition of compound of Formula Ias the hydrochloride salt: (N-oleyl-N-(3-trimethoxysilyl)propyl ammoniumchloride at 50 wt % in methanol) Added (grams of 50% 133.8 133.8 133.8133.8 soln.) Addition period (mins) 5 5 5 5 Temp. at addition (° C.) 5857.8 56.2 52 (c) Addition of caustic after calculation of the equivalentbalance (EB) Caustic concentration 5.5/66 5.5/66 5.5/66 5.5/66(NaOH/H₂O, g/g) Addition period (mins) 5 5 5 5 Temp. at addition (° C.)58 57.8 56.2 52 (d) Addition of the coupling agent,bis(triethoxysilylpropyl)tetrasulfane (Si-69) to the silica surfaceSi-69 weight, kgs. 1.07 1.07 1.07 1.07 Addition period, mins 30 30 30 30Reaction time (hours) 1.25 1.25 1.5 1.5 Initial Temperature (° C.) 58 5756 52 (e) Addition of compound of Formula II as the hydrochloride salt:(N-oleyl-N-(3-trimethoxysilyl)propyl ammonium chloride at 50 wt % inmethanol Amt. Added (kgs 50% 1.2 1.2 1.2 1.2 soln.) Addition period(mins) 5 5 5 5 Reaction time (mins) 5 5 5 5 (f) Addition of causticafter calculation of Equivalent Balance Caustic concentration 52.2/66052.2/500 52.2/660 52.2/660 (NaOH/H₂O, grams/ grams) Addition period(mins) 5 5 5 5 Reaction time (mins) 5 5 5 5

3) Cement/Silica slurry mixing

On day 1, the first batch prepared slurry was added to the cement in T1by vacuum transfer. Four liters of water were used to wash down thesides of R1 and the washings were similarly transferred. No agitationwas used on T1. On day 2 and day 3 the process was repeated. On day 420.0 kg. of Sundex 8125 aromatic process oil was added to T1 from a topmanhole. The final batch of silica slurry was then added and theagitator speed was increased to 200 rpm and heat was applied to thejacket on T1. After a temperature of 50 degrees Celsius had beenattained, the heating and agitation were stopped and the reactor wasallowed to remain in a quiescent state for 30 minutes.

4) Coagulation

The mixture in T1 was pressurised by nitrogen directly into T2coagulation vessel maintained at 92-95 degrees Celsius by means of lowpressure steam. The air-driven agitator was started at ˜50-60 rpm. Thelow speed gave a crumb size of approximately 1 cm and providedsufficient agitation to prevent the cement from forming a surface cakeon the water.

5) Finishing

The crumb from the coagulation vessel T2 was passed over a Sweco shakerscreen for preliminary dewatering and then allowed to sit for an hour onan open tray. The initial moisture level measured on the trayed materialaveraged 54%. Two trays of wet product at ambient temperature werepassed once through the dewatering rocket. The feeding characteristicsof the material were excellent even at the highest screw speed and itrequired two operators to manually feed the material to the extruder inorder to keep up with the discharge rate. The exit temperature wasjudged to be approximately 35 degrees Celsius, and the one-pass materialhad a moisture level of 31.1 %, or approximately 42% reduction in watercontent. The product was reasonably cohesive with the appearance of longstrands of spaghetti. One half of this stranded product was segregatedfor drying tests and the other half was passed two more times throughthe extruder to give a further reduction in moisture to a final 16.3%.During the second and particularly third passes, only a small amount ofwater was recovered from the rear discharge but the product on exitingthe extruder periodically squirted water from within the material. Theexit temperature of the product on the third pass was approximately 55degrees Celsius. The 3-pass product had remarkable green strength for astill-wet material and considerable force was required to break thestrands manually.

The 20 full trays obtained were then stacked in the forced air dryersmaintained at 85 degrees Celsius and dried for 6 hours. The agglomerateddried product cake was passed through a Cumberland grinder to homogenizeit and then bagged. Yield was approximately 141 kg., ˜96.4% oftheoretical.

Characterization/Testing of Product

The moisture levels measured using a moisture balance set at 105 degreesCelsius on the dried unextruded product average 0.27%, on the one-passmaterial 0.26%, but on the 3-pass material it was still 2.4%.

Ash levels on the finished product, were determined by calcining at 700degrees Celsius.

The results from the limited characterization of the product are shownbelow in Table 2.

TABLE 2 Product Characterization Tray # Moisture % Ash % (700° C.)  10.32 n/a  2 n/a 33.34  3 0.29 n/a  4 n/a 33.69  5 0.23 n/a  6 n/a 32.1  7 0.18 n/a  8 0.24 32.3   9 n/a n/a 10 0.16 n/a 11 0.29 n/a 12 n/a n/a13 0.32 n/a 14 n/a 30.9  15 0.22 n/a 16 0.27 n/a 17 n/a n/a 18 0.2631.62 (one-extruder pass) AVERAGE 0.25 32.3 

EXAMPLE II

1) Cement Preparation

A solution of an oil extended SBR rubber was prepared by adding Buna VSL5025-1 (Buna VSL 1950 S25), previously cut into small pieces, to hexanein T1. Dissolution was effected by heating to 60 degrees Celsius withstirring. At the time of the trial, T1 held the equivalent of 62.84 kgof Buna VSL 5025-1 in 183.6 kg of hexane, giving a cement containing25.5 wt. % polymer plus oil. The cement was stabilized by adding 0.34kilos each of Polygard and Irganox 1076.

2) Hydrophobicized Silica Slurry Preparation

Two batches of silica slurry were prepared; this was done over a two dayperiod: The recipes/procedures used are shown in Table 3 following. Theagitation rate on R1 was set at ˜250 rpm during all steps on both days.

TABLE 3 Preparation of Hydrophobicized Silica Slurry Sub-StepParameters: /Date DAY 1 DAY 2 (a) Slurry preparation Water (kg) 85.3460.71 Water Temperature (° C.) 60 60 HiSil-233 silica (kg) 21.37 15.2Stirring time (mins) 5 5 Final Temperature (° C.) 52 52 (b) Addition ofa compound of Formula I as the hydrochloride salt:(N-oleyl-N-(3-trimethoxysilyl)propyl ammonium chloride at 50 wt % inmethanol Added (grams of 50% soln.) 213.6 151.9 Addition period (mins) 55 Temp. at addition (° C.) 52 52 (c) Addition of caustic aftercalculation of equivalent balance Caustic concentration 8.55/75 6.08/50(NaOH/H₂O), grams/grams) Addition period (mins) 5 5 Temp. at addition (°C.) 52 52 (d) Addition of coupling agent Si-69 to the silica surface:Si-69 weight, kgs. 1.71 1.21 Addition period, mins 30 30 Reaction time(hours) 1.25 1.25 Initial Temperature (° C.) 52 52 Final Temperature (°C.) 48.6 46.6 (e) Addition of compound of Formula II as thehydrochloride salt (N-oleo-N-(3-trimethoxysilyl)propyl ammonium chlorideat 50 wt % in methanol Amt. Added (kgs 50% soln.) 1.92 1.37 Additionperiod (mins) 5 5 Temp. at addition (° C.) 48.6 46.6 Reaction time(mins) 5 5 Final Temperature (° C.) 47.2 46 (f) Addition of causticafter calculation of equivalent balance Caustic concentration 83.1/70059.3/500 (NaOH/H₂O, grams/grams) Addition period (mins) 5 5 Temp. ataddition (° C.) 47.2 46 Reaction time (mins) 5 5 Final Temperature (°C.) 47 45.4

3): Cement/Silica slurry mixing

On day 1 the first batch prepared slurry was added to the 60 degreesCelsius cement in T1 by vacuum transfer. Four liters of water were usedto wash down the sides of R1 and the washings were similarlytransferred. T1 was stirred under mild agitation and 60 degrees Celsiusthermostatting overnight. On day 2, the second batch of slurry was addedto T1, again by vacuum transfer, R1 was washed again with 4 liters ofwater and the washings added to T1. The agitator speed was increased to200 rpm for 10 minutes after which agitation was stopped. After standingfor 15 minutes, some of the water layer from the bottom of T1 wascautiously removed to ascertain the extent of transfer of the silica tothe cement (organic phase). The first 2 liters of the water phasecontained an estimated 150 grams of coated silica from the piping deadspace in front of the valve. The remainder of the water phase was clearalthough slightly yellowish. Following the sampling, the vessel T1 wasagain put under mild agitation in preparation for coagulation. Due tothe minor amount of untransferred silica, no corrections were made tothe formulation.

4) Coagulation

The mixture in T1 was pressurised by nitrogen directly into T2coagulation vessel maintained at 92-95 degrees Celsius by means of lowpressure steam. The agitator speed was adjusted downward to ˜100 rpm andfinally to ˜50-60 rpm. The low speed was found adequate to maintain acrumb size of approximately 1 cm while still preventing the preblendfrom forming a surface cake on the water. A flow rate of 1 kg/min ofmaterial from T1 into the coagulator was found satisfactory todevolatilize the crumb. The entire contents of T1 were coagulated in onepass.

5) Finishing

The crumb from the coagulation vessel T2 was passed over a Sweco shakerscreen for preliminary dewatering and then allowed to sit for an hour onan open tray. The initial moisture level measured on the trayed materialwas 60-65%. The 18 full trays obtained were then stacked in the forcedair dryers maintained at 85-90 degrees Celsius and dried for 4-6 hours.During this period the product was turned over once by hand to provideeven drying. The agglomerated dried product cake was passed through aCumberland grinder to homogenize it and then bagged. Yield wasapproximately 99 kg., 95.3% of theoretical.

Characterization/Testing of Product

Final moisture levels on the dried product ranged from 0.2-0.5%,measured on a moisture balance set at 105 degrees Celsius.Thermo-gravimetric analysis (TGA) on the finished product indicated anash level of 31.72%.

EXAMPLE III

A masterbatch of a silica-filled vinyl solution styrene butadiene rubber(SSBR MB), the product of Example I, was converted to a vulcanizedrubber for use in tire treads. For comparison there was also tested adry blend of the same rubber, mixed with silica particles that had notbeen hydrophobicized in accordance with the invention.

The masterbatch (228 parts), composed of 100 parts of rubber, 37.5 partsof aromatic oil extender, 80 parts of silica particles hydrophobicizedin accordance with the invention by treatment withN-oleyl-N-(3-trimethoxysilyl)propyl ammonium chloride, withbis(triethoxysilylpropyl)sulfane (Si-69) (6.4 parts) and again withN-oleyl-N-(3-trimethoxysilyl)propyl ammonium chloride was placed in aBanbury mixer, BR-82 (Capacity 1.6 liters) under the followingconditions:

Speed: 77 RPM

Start Temperature: 40° C.

Ram Pressure: 30 psi

Mokon: Set at 25° C.

To the masterbatch there were added stearic acid (1 part) and zinc oxide(2.5 parts) as activators, and these were mixed for 180 seconds. Anyingredients that had risen onto the surface and escaped from the mass inthe mixer were swept back into the mass and mixing continued for afurther 60 seconds, after which time the mixture was dumped from theBanbury mixer. To the mixture on a warm mill there were then addedsulphur (1.4 parts), an accelerator Vulkacit CZ/EG-C(CBS) (1.7 parts)and a further accelerator Vulkacit D/C (DPG) 2 parts. These ingredientswere refined on the mill (6 passes) to give a product whose specificgravity was 1.193. The total mixing time taken, from commencing mixingin the Banbury mixer to the completion of mill mixing, was 8 minutes.

For the dry mix, vinyl solution styrene butadiene rubber containing 100parts polymer and 37.5 parts aromatic oil extender were placed in theBanbury mixer and mixed for 60 seconds. After 60 seconds, there wereadded untreated silica particles (Hi-Sil 233, 40 parts) and Si-69coupling agent (3.2 parts) and mixing continued for a further 60seconds. After 120 seconds, a further 40 parts of untreated silicaparticles and 3.2 parts of Si-69 were added and ingredients that hadescaped from the mass were swept back into the mass, and mixingcontinued for a further 60 seconds. After 180 seconds, the ram of themixer was raised, escaped ingredients were swept back into the mass, theram lowered and mixing continued for a further 60 seconds. After 240seconds, escaped ingredients were again swept back into the mass andstearic acid (1 part) and zinc oxide (2.5 parts) were added. Mixing wasresumed, and after 300 seconds escaped ingredients were swept back intothe mass, and mixing continued. After 420 seconds, the mass was dumpedout of the mixer and formed into a sheet.

The mixer was allowed to cool to 40° C., then the mass was returned tothe mixer and mixing continued until the temperature of the ramtemperature probe reached 150° C. The mass was then dumped out. To themixture on a warm mill there were then added sulphur (1.4 parts).Vulkacit CZ/EG-C (CBS) (1.7 parts) and Vulkacit D/C (DPG) (2 parts) andthese ingredients refined on the mill (6 passes) to give a product whosespecific gravity was 1.195. The total mixing time from commencement ofmixing was 15.5 minutes.

The silica dry mix and the masterbatch of the invention were thensubjected to tests whose results are given below:

VSBR Silica Dry Mix vs Masterbatch

SILICA DRY MIX SSBR MB COMPOUND MOONEY VISCOSITY ML 1 + 4′ @ 100° C.(MU) 61.9 78.6 Mooney Relaxation: Time to Decay 80% (min) 0.16 0.25COMPOUND MOONEY SCORCH Rotor Size: large t5 @ 138° C. (min) >30 7.8STRESS STRAIN (DUMBELLS) Cure time (min) 25 18 Cure Temperature: 166° C.Stress @ 25% elongation (MPa) 1.1 0.95 Stress @ 50% elongation (MPa) 1.81.5 Stress @ 100% elongation (MPa) 3.8 3.1 Stress @ 200% elongation(MPa) 10.5 7.4 Stress @ 300% elongation (MPa) — 14.4 Tensile (MPa) 13.814.4 Elongation (%) 240 300 Hardness (Å) 68 64 Tensile × Elongation/10033.1 43.2 DIE C TEAR Cure Time (min) 25 18 Cure Temperature 166° C. TearStrength (kN/m) 26.9 42.6 DIN Abrasion Volume Loss (mm³) 123 105Compound #1 Compound #2 1950S25 XQ209 ZWICK REBOUND Cure Time (min) 3023 Cure Temperature: 166° C. Resilience @ 0° C. (%) 4.6 5.0 Resilience @23° C. (%) 13.1 13.0 Resilience @ 100° C. (%) 61.0 64.6 GOODRICHFLEXOMETER Cure Time (min) 30 23 Cure Temperature: 166° C. AmbientTemperature: 55° C. Load on Beam: 11 kg Stroke (Compression): 17.5% HeatRise (° C.) 16.3 14.7 Permanent Set (%) 2.0 1.5 MER 1100 DynamicProperties Frequency: 20 Hz @ 60° C. Load: 7% static ± 3% dynamic StaticStiffness (kg/mm) 2.93 3.94 Dynamic Stiffness (kg/mm) 6.33 6.49Ratio-dynamic:static 2.16 1.65 Power Loss (g.m/sec) 1.25 1.28 Tan Delta0.149 0.148

These results suggest that, when used in tire treads, the product fromthe masterbatch will display lower rolling resistance, better abrasionresistance and equal traction characteristics, when compared with thesilica dry mix.

EXAMPLE IV

A masterbatch of a high cis polybutadiene rubber, the product of ExampleII, was converted to a vulcanized rubber for use in tire treads. Forcomparison there was also tested a dry blend mix of the same rubbermixed with silica particles that had not been hydrophobicized inaccordance with the invention.

The masterbatch (220.4 parts) composed of 100 parts of rubber, 30.0parts aromatic extender oil, 80 parts of silica particleshydrophobicized in accordance with the invention by treatment withN-oleyl-N-(3-trimethoxysilyl)propyl ammonium chloride, with Si-69 (6.4parts) and again with N-oleyl-N-(3-trimethoxysilyl)propyl ammoniumchloride was placed in the same Banbury mixer as used in Example III,and mixed with stearic acid (1 part) and zinc oxide (2.5 parts) underthe same conditions as in Example III. Thereafter, the mixture wasdumped from the Banbury mixer and mixed with sulphur (1.4 parts),Vulkacit CZ/EG-C(CBS) (1.7 parts) and Vulkacit D/C (DPG) (2 parts) on awarm mill. The ingredients were refined (6 passes) to yield a productwhose specific gravity was 1.193. The total mixing time was 8 minutes.

The dry mix of rubber (100 parts) untreated silica (80 parts) Si-69 (6.4parts) stearic acid (1 part) aromatic extender oil (30 parts) and zincoxide (2.5 parts) were mixed in the Banbury mixer under the same regimeas described in Example III. Thereafter the mixture was admixed on awarm mill with sulphur (1.4 parts) Vulkacit CZ/EG-C(CBS) (1.7 parts) andVulkacit D/C (DPG) (2 parts). The product had a specific gravity of1.190. The total mixing time was 15.5 minutes.

The vulcanizates produced from the silica dry mix and the masterbatch ofthe invention were then subjected to tests whose results are givenbelow:

BR Silica Masterbatchs

TAKTENE 1203 + Silica Silica mb COMPOUND MOONEY VISCOSITY ML 1 + 4′ @100° C. (MU) 64.9 71.3 Mooney Relaxation: Time to Decay 80% (min) 0.200.23 COMPOUND MOONEY SCORCH Rotor Size: large t5 @ 138° C. (min) 22.755.86 STRESS STRAIN (DUMBELLS) Cure time (min) 13 8 Cure Temperature:166° C. Stress @ 25% elongation (MPa) 1.2 0.97 Stress @ 50% elongation(MPa) 1.7 1.4 Stress @ 100% elongation (MPa) 2.7 2.1 Stress @ 200%elongation (MPa) 5.9 5.0 Stress @ 300% elongation (MPa) 10.6 9.4M300:M100 3.93 4.48 Tensile (MPa) 15.6 14.2 Elongation (%) 395 400Hardness (Å) 67 72 Tensile × Elongation/100 61.62 56.8 DIE B TEAR CureTime (min) 13 8 Cure Temperature: 166° C. Tear Strength (kN/m) 63.0 75.1DIE C TEAR Cure Time (min) 13 8 Cure Temperature: 166° C. Tear Strength(kN/m) 34.5 32.7 DIN Abrasion Volume Loss (mm³) 61 54 Compound #3Compound #4 TAKTENE XQ 211 BR 1203 + Silica Silica mb ZWICK REBOUND CureTime (min) 18 13 Cure Temperature: 166° C. Resilience @ 0° C. (%) 53.053.0 Resilience @ 23° C. (%) 56.8 55.0 Resilience @ 100° C. (%) 61.465.0 GOODRICH FLEXOMETER Cure Time (min) 18 13 Cure Temperature: 166° C.Ambient Temperature: 55° C. Load on Beam: 11 kg Stroke (Compression):17.5% Heat Rise (° C.) 25.3 22.0 Permanent Set (%) 2.4 2.3 MER 1100Dynamic Properties Frequency: 20 Hz @ 60° C. Load: 7% static ± 3%dynamic Static Stiffness (kg/mm) 5.68 4.41 Dynamic Stiffness (kg/mm)9.25 8.14 Ratio-dynamic:static 1.63 1.85 Power Loss (g.m/sec) 1.56 1.29Tan Delta 0.129 0.126

Again, the results suggest that a tire tread vulcanizate produced fromthe masterbatch will display lower rolling resistance and betterabrasion resistance, with equal traction characteristics, when comparedwith a tire tread vulcanizate produced from the dry mix.

What is claimed is:
 1. A process for treating particles comprising thesteps of: contacting the particles with a compound of Formula I:

 or an acid addition or quaternary ammonium salt thereof, in which: R¹,R² and R³ is selected from a hydroxyl group and a hydrolysable group; R⁴is a divalent group that is resistant to hydrolysis at the Si—R⁴ bond:R⁵ is selected from the group comprising: hydrogen; a C₁₋₄₀ alkyl: aC₆-C₄₀ aryl group; a C₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group;a group of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴, which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³, which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula:

 wherein r is an integer from 1 to 6 and d is an integer from 1 to 4; R⁶may be any of the groups defined for R⁵, or R⁵ and R⁶ may together forma divalent group of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀ alkenyl group, a C₆-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and v are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6; and contacting the particles with a compound of the FormulaII:

 in which: R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³;and R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or aC₈₋₄₀ mono-, di- or tri-unsaturated alkenyl group, either of which canbe interrupted by one or more aryl groups; a group of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, the aromatic group being unsubstituted or substituted bya C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturated alkenyl group; andR²⁰ may be any of the groups defined for R¹⁹, with the provisos that R¹⁹and R²⁰ do not have a tertiary carbon atom adjacent to the nitrogen atomand that at least one of R¹⁹ and R²⁰ has a carbon chain at least 8carbon atoms in length uninterrupted by any heteroatoms.
 2. The processdefined in claim 1, wherein Steps (a) and (b) are conductedconcurrently.
 3. The process defined in claim 1, wherein Steps (a) and(b) are conducted sequentially.
 4. The process defined in claim 1,wherein Formulae I and II are different compounds.
 5. The processdefined in claim 1, wherein Step (a) comprises contacting an aqueousslurry of the particles with the compound of Formula I.
 6. The processdefined in claim 5, wherein the compound of Formula I is a solutioncomprising a solvent which is substantially water miscible.
 7. Theprocess defined in claim 1, wherein the particles are mineral particlesthat are hydrophilic and have surface hydroxyl groups.
 8. The processdefined in claim 1, wherein the particles are silica particles.
 9. Theprocess defined in claim 1, wherein: R¹ is selected from the groupconsisting of hydroxyl groups, groups of formula OC_(p)H_(2p+1), where phas a value from 1 to 10 and the alkyl chain may be interrupted by oneor more oxygen atoms, phenoxy, acetoxy, chloro, bromo, iodo, ONa, OLi,OK, amino and mono- and dialkylamino, R² is selected from the groupconsisting of hydroxy) groups, groups of formula OC_(p)H_(2p+1) where phas a value from 1 to 10 and the alkyl chain may be interrupted by oneor more oxygen atoms, phenoxy, acetoxy, ONa, OLi, OTC, amino mono- anddialkylamino, C₁₋₁₀, alkyl, C₂₋₁₀ mono- and di-unsaturated alkenyl,phenyl and groups of the formula: —R⁴—NR⁵ R⁶  wherein R⁴, R⁵, R⁶ are asdefined in claim
 1. 10. The process defined in claim 1, wherein: R¹⁵ isselected from the group consisting of hydroxyl groups, groups of formulaOC_(p)H_(2p+1), where p has a value from 1 to 10 and the alkyl chain maybe interrupted by one or more oxygen atoms, phenoxy, acetoxy, chloro,bromo, iodo, ONa, OLi, OK, amino and mono- and dialkylamino, R¹⁶ isselected from the group consisting of hydroxyl groups, groups of formulaOC_(p)H_(2p+1) where p has a value from 1 to 10 and the alkyl chain maybe interrupted by one or more oxygen atoms, phenoxy, acetoxy, ONa, OLi,OK, amino, mono- and dialkylamino, C₁₋₁₀ alkyl, C₂₋₁₀ mono- anddi-unsaturated alkenyl, phenyl and groups of formula: —R¹⁸—NR¹⁹R²⁰—  inwhich R¹⁸ is a divalent group resistant to hydrolysis.
 11. The processdefined in claim 1, wherein the particulate material comprises mineralparticles.
 12. The process defined in claim 11, wherein the mineralparticles are selected from the group consisting of silicates, silicas,clay, titanium dioxide, alumina, calcium carbonate, zinc oxide andmixtures thereof.
 13. The process defined in claim 11, wherein themineral particles comprise silica made by carbon dioxide precipitationof sodium silicate.
 14. Particulate material which has been produced bythe process defined in claim
 1. 15. A particulate material comprisingparticles having bound thereto an aminohydrocarbonsilane moiety havingthe formula

in which: R^(a), R^(b) and R^(c) are the same or different and each isselected from —O— and —C_(p)H_(2p)—, optionally substituted by one ormore oxygen atoms and wherein p is an integer of from 1 to 10; and R¹²is a C₈₋₄₀ alkyl group; a C₈₋₄₀ mono-, di- or tri-unsaturated alkenylgroup; a group of formula

 or an acid addition or quaternary ammonium salt thereof in which R⁴ isa divalent group resistant to hydrolysis at the Si—R⁴ bond, R⁵ ishydrogen, C₁₋₄₀ alkyl, C₂₋₄₀ mono-, di- or tri- unsaturated alkenyl; agroup of formula —ArCH_(w)H_(2w+1)  in which Ar represents a divalentaromatic group and w is an integer from 1 to 20, and R⁶ may be any ofthe groups defined for R⁵, with the proviso that at least one of R⁵ andR⁶ must have an uninterrupted carbon chain at least 8 carbon atoms inlength.
 16. A particulate material comprising particles having: (i)bound thereto an aminohydrocarbonsilane moiety, and (ii) a contact anglewith water of at least about 100°.
 17. The particulate material definedin claim 16, wherein the contact angle of at least about 110°.
 18. Theparticulate material defined in claim 16, wherein the contact angle isin the range of from about 115° to about 160°.
 19. The particulatematerial defined in claim 16, wherein the contact angle is in the rangeof from about 120° to about 150°.
 20. The particulate material definedin claim 16, wherein the contact angle is in the range of from about120° to about 140°.
 21. The particulate material defined in claim 16,wherein the aminohydrocarbonsilane moeity has the formula

in which: R^(a), R^(b) and R^(c) are the same or different and each isselected from —O— and —C_(p)H_(2p)—, optionally substituted by one ormore oxygen atoms and wherein p is an integer of from 1 to 10; and R¹²is a C₈₋₄₀ alkyl group; a C₈₋₄₀ mono-, di- or tri-unsaturated alkenylgroup; a group of formula

 or an acid addition or quaternary ammonium salt thereof in which R⁴ isa divalent group resistant to hydrolysis at the Si—R⁴ bond, R⁵ ishydrogen, C₁₋₄₀ alkyl, C₂₋₄₀ mono-, di- or tri-unsaturated alkenyl; agroup of formula —ArC_(w)H_(2w+1)  in which Ar represents a divalentaromatic group and w is an integer from 1 to 20, and R⁶ may be any ofthe groups defined for R⁵, with the proviso that at least one of R⁵ andR⁶ must have an uninterrupted carbon chain at least 8 carbon atoms inlength.
 22. The particulate material defined in claim 15, wherein theparticulate material comprises mineral particles.
 23. The particulatematerial defined in claim 22, wherein the mineral particles are selectedfrom the group consisting of silicates, silicas, clay, titanium dioxide,alumina, calcium carbonate, zinc oxide and mixtures thereof.
 24. Theparticulate material defined in claim 22, wherein the mineral particlescomprise silica made by carbon dioxide precipitation of sodium silicate.25. The particulate material defined claim 15, wherein the particulatematerial comprises non-mineral particles.
 26. The particulate materialdefined in claim 25, wherein the non-mineral particles comprise carbonblack.
 27. The process defined in claim 1, wherein two of R¹, R² and R³are selected from a hydroxyl group and a hydrolysable group.
 28. Theprocess defined in claim 1, wherein each of R¹, R² and R³ are selectedfrom a hydroxyl group and a hydrolysable group.
 29. The process definedin claim 1, wherein the sum of t and v is
 4. 30. The process defined inclaim 1, wherein R¹² is selected from the group comprising a C₈₋₄₀ alkylgroup or a C₈₋₄₀ mono-, di- or tri-unsaturated alkenyl group, either ofwhich can be interrupted by one or more phenyl groups.
 31. A process fortreating particles to render them hydrophobic, the process comprisingthe following steps in sequence of: (a) contacting the particles with acompound of Formula I:

 or an acid addition or quaternary ammonium salt thereof, in which: atleast one of R¹, R² and R³ is selected from a hydroxyl group and ahydrolysable group; R⁴ is a divalent group that is resistant tohydrolysis at the Si—R⁴ bond; R⁵ is selected from the group comprising:hydrogen; a C₁₋₄₀ alkyl; a C₅-C₄₀ aryl group; a C₂₋₄₀ mono-, di- ortri-unsaturated alkenyl group; a group of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴, which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³, which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula: —|(CH₂)_(r)NH|_(d)—H  wherein ris an integer from 1 to 6 and d is an integer from 1 to 4; R⁶ may be anyof the groups defined for R⁵, or R⁵ and R⁶ may together form a divalentgroup of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀ alkenyl group, a C₅-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and v are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6; and (b) contacting the particles with a compound of theFormula II:

 in which: R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³;and R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or aC₈₋₄₀ mono-, di- or tri-unsaturated alkenyl group, either of which canbe interrupted by one or more aryl groups; a group of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, the aromatic group being unsubstituted or substituted bya C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturated alkenyl group; andR²⁰ may be any of the groups defined for R¹⁹, with the provisos that R¹⁹and R²⁰ do not have a tertiary carbon atom adjacent to the nitrogen atomand that at least one of R¹⁹ and R²⁰ has a carbon chain at least 8carbon atoms in length uninterrupted by any heteroatoms.
 32. A processfor treating particles to render them hydrophobic, the processcomprising the steps of: (a) contacting the particles with a compound ofFormula 1:

 or an acid addition or quaternary ammonium salt thereof, in which: atleast one of R¹, R² and R³ is selected from a hydroxyl group and ahydrolysable group; R⁴ is a divalent group that is resistant tohydrolysis at the Si—R⁴ bond; R⁵ is selected from the group comprising:hydrogen; a C₁₋₄₀ alkyl; a C₅-C₄₀ aryl group; a C₂₋₄₀ mono-, di- ortri-unsaturated alkenyl group; a group of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴, which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³, which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula: —|(CH₂)_(r)NH|_(d)—H  wherein ris an integer from 1 to 6 and d is an integer from 1 to 4; R⁶ may be anyof the groups defined for R⁵, or R⁵ and R⁶ may together form a divalentgroup of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀ alkenyl group, a C₅-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and V are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6; and (b) contacting the particles with a compound of theFormula II;

 in which: R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³;and R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or aC₈₋₄₀ mono-, di- or tri-unsaturated alkenyl group, either of which canbe interrupted by one or more aryl groups; a group of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, the aromatic group being unsubstituted or substituted bya C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturated alkenyl group; andR²⁰ may be any of the groups defined for R¹⁹, with the provisos that R¹⁹and R²⁰ do not have a tertiary carbon atom adjacent to the nitrogen atomand that at least one of R¹⁹ and R²⁰ has a carbon chain at least 8carbon atoms in length uninterrupted by any heteroatoms; whereinFormulae I and II are the same compound.
 33. A process for treatingparticles to render them hydrophobic, the process comprising the stepsof: (a) contacting the particles with a compound of Formula I:

 or an acid addition or quaternary ammonium salt thereof, in which: atleast one of R¹, R² and R³ is selected from a hydroxyl group and ahydrolysable group; R⁴ is a divalent group that is resistant tohydrolysis at the Si—R⁴ bond; R⁵ is selected from the group comprising:hydrogen; a C₁₋₄₀ alkyl; a C₅-C₄₀ aryl group; a C₂₋₄₀ mono-, di- ortri-unsaturated alkenyl group; a group of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴ ₁ which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³, which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula: —|(CH₂)_(r)NH|_(d)—H  wherein ris an integer from 1 to 6 and d is an integer from 1 to 4; R⁶ may be anyof the groups defined for R⁵, or R⁵ and R⁶ may together form a divalentgroup of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀ alkenyl group, a C₅-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and v are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6; and (b) contacting the particles with a compound of theFormula II:

 in which: R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³;and R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or aC₈₋₄₀ mono-, di- or tri-unsaturated alkenyl group, either of which canbe interrupted by one or more aryl groups; a group of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, the aromatic group being unsubstituted or substituted bya C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturated alkenyl group; andR²⁰ may be any of the groups defined for R¹⁹, with the provisos that R¹⁹and R²⁰ do not have a tertiary carbon atom adjacent to the nitrogen atomand that at least one of R¹⁹ and R²⁰ has a carbon chain at least 8carbon atoms in length uninterrupted by any heteroatoms; wherein theparticles are contacted with a coupling agent after the addition of thecompound of Formula I but before the addition of the compound of FormulaII.
 34. The process according to claim 33, wherein the coupling agent isselected from the group consisting ofbis[3-(triethoxysilyl)propyl]tetrasulfane,bis[3-(triethoxysilyl)propyl]tetrasulfane,bis[2-(trimethoxysilyl)ethyl]tetrasulfane and mixtures thereof.
 35. Aprocess for treating particles to render them hydrophobic, the processcomprising the steps of: (a) contacting the particles with an acidaddition or quaternary ammonium salt of a compound of Formula I:

 in which: at least one of R¹, R² and R³ is selected from a hydroxylgroup and a hydrolysable group; R⁴ is a divalent group that is resistantto hydrolysis at the Si—R⁴ bond; R⁵ is selected from the groupcomprising: hydrogen; a C₁₋₄₀ alkyl; a C₅-C₄₀ aryl group; a C₂₋₄₀ mono-,di- or tri-unsaturated alkenyl group; a group of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴, which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³, which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula: —|(CH₂)_(r)NH|_(d)—H  wherein ris an integer from 1 to 6 and d is an integer from 1 to 4; R⁶ may be anyof the groups defined for R⁵, or R⁵ and R⁶ may together form a divalentgroup of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀, alkenyl group, a C₅-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and v are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6; and (b) contacting the particles with a compound of theFormula II:

 in which: R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³;and R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or aC₈₋₄₀ mono-, di- or tri-unsaturated alkenyl group, either of which canbe interrupted by one or more aryl groups; a group of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, the aromatic group being unsubstituted or substituted bya C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturated alkenyl group; andR²⁰ may be any of the groups defined for R¹⁹, with the provisos that R¹⁹and R²⁰ do not have a tertiary carbon atom adjacent to the nitrogen atomand that at least one of R¹⁹ and R²⁰ has a carbon chain at least 8carbon atoms in length uninterrupted by any heteroatoms.
 36. A processaccording to claim 35, wherein compound of Formula I isN-oleyl-N-(3-trimethoxysilyl)propyl ammonium dichloride or an acidaddition or quaternary ammonium salt thereof.
 37. A process for treatingparticles to render them hydrophobic, the process comprising the stepsof: (a) contacting the particles with a compound of Formula I:

 or an acid addition or quaternary ammonium salt thereof, in which: atleast one of R¹, R² and R³ is selected from a hydroxyl group and ahydrolysable group; R⁴ is a divalent group that is resistant tohydrolysis at the Si—R⁴ bond; R⁵ is selected from the group comprising:hydrogen; a C₁₋₄₀ alkyl; a C₅-C₄₀ aryl group; a C₂₋₄₀ mono-, di- ortri-unsaturated alkenyl group; a group of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴, which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ a mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³, which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula: —|(CH₂)_(r)NH|_(d)—H  wherein ris an integer from 1 to 6 and d is an integer from 1 to 4; R⁶ may be anyof the groups defined for R⁵, or R⁵ and R⁶ may together form a divalentgroup of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀ alkenyl group, a C₅-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and v are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6; and (b) contacting the particles with a compound of theFormula II:

 in which: R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³;and R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or aC₈₋₄₀ mono-, di- or tri-unsaturated alkenyl group, either of which canbe interrupted by one or more aryl groups; a group of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, the aromatic group being unsubstituted or substituted bya C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturated alkenyl group; andR²⁰ may be any of the groups defined for R¹⁹, with the provisos that R¹⁹and R²⁰ do not have a tertiary carbon atom adjacent to the nitrogen atomand that at least one of R¹⁹ and R²⁰ has a carbon chain at least 8carbon atoms in length uninterrupted by any heteroatoms; wherein thecompound of Formula II is N-oleyl-N-(3-trimethoxysilyl)propyl ammoniumdichloride or an acid addition or quarternary ammonium salt thereof. 38.A process for treating particles to render them hydrophobic, the processcomprising the steps of: (a) contacting the particles with a compound ofFormula I:

 or an acid addition or quaternary ammonium salt thereof, in which: atleast one of R¹, R² and R³ is selected from a hydroxyl group and ahydrolysable group; R⁴ is a divalent group that is resistant tohydrolysis at the Si—R⁴ bond; R⁵ is selected from the group comprising:hydrogen; a C₁₋₄₀ alkyl; a C₅-C₄₀ aryl group; a C₂₋₄₀ mono-, di- ortri-unsaturated alkenyl group; a group of the formula:

 in which x is an integer from 2 to 10, R¹³ and R¹⁴, which may be thesame or different, are each hydrogen; C₁₋₁₈ alkyl; C₂₋₁₈ mono-, di- ortri-unsaturated alkenyl; phenyl; a group of formula:

 wherein b is an integer from 1 to 10; a group of formula:

 wherein c is an integer from 1 to 10 and R²² and R²³, which may be thesame or different, are each hydrogen, C₁₋₁₀ alkyl group or C₂₋₁₀ alkenylgroup, provided that there is no double bond in the position alpha tothe nitrogen atom; a group of formula: —|(CH₂)_(r)NH|_(d)—H  wherein ris an integer from 1 to 6 and d is an integer from 1 to 4; R⁶ may be anyof the groups defined for R⁵, or R⁵ and R⁶ may together form a divalentgroup of formula:

 in which A is selected from the group comprising —CHR or —NR group inwhich R is hydrogen or a C₁₋₄₀ alkyl or C₂₋₄₀ alkenyl group, a C₅-C₄₀aryl group, an oxygen atom and a sulfur atom, and t and v are eachindependently 1, 2, 3 or 4; provided that the sum of t and v does notexceed 6; and (b) contacting the particles with a compound of theFormula II:

 in which: R¹⁵, R¹⁶ and R¹⁷ have the same definitions as R¹, R² and R³;and R¹² is selected from the group comprising a C₈₋₄₀ alkyl group or aC₈₋₄₀ mono-, di- or tri-unsaturated alkenyl group, either of which canbe interrupted by one or more aryl groups; a group of formula:

 or an acid addition or quaternary ammonium salt thereof in which R¹⁸ isa divalent group resistant to hydrolysis at the Si—R¹⁸ bond, R¹⁹ isselected from the group comprising hydrogen, a C₁₋₄₀ alkyl group, aC₂₋₄₀ mono-, di- or tri-unsaturated alkenyl group, a substitutedaromatic group, the aromatic group being unsubstituted or substituted bya C₁₋₂₀ alkyl or C₂₋₂₀ mono-, di- or tri-unsaturated alkenyl group; andR²⁰ may be any of the groups defined for R¹⁹, with the provisos that R¹⁹and R²⁰ do not have a tertiary carbon atom adjacent to the nitrogen atomand that at least one of R¹⁹ and R²⁰ has a carbon chain at least 8carbon atoms in length uninterrupted by any heteroatoms, wherein theparticulate material comprises non-mineral particles.
 39. A processaccording to claim 38, wherein said non-mineral particles comprisecarbon black.